Global Logger

logger.go

package globallogger

import (
    "log"
    "os"
    "sync"
)

type logger struct {
    filename string
    *log.Logger
}

var logger *logger
var once sync.Once

func Get() *logger {
    once.Do(func() {
        logger = createLogger("mylogger.log")
    })
    return logger
}

func createLogger(fname string) *logger {
    file, _ := os.OpenFile(fname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0777)
    return &logger{
        filename: fname,
        Logger:   log.New(file, "My App Name ", log.Lshortfile),
    }
}

main.go

package main

import (
    "customlogger"
    "fmt"
    "net/http"
)

func main() {
    logger := globallogger.Get()
    logger.Println("Starting")

    http.HandleFunc("/", sroot)
    http.ListenAndServe(":8080", nil)
}

func sroot(w http.ResponseWriter, r *http.Request) {
    logger := globallogger.Get()

    fmt.Fprintf(w, "welcome")
    logger.Println("Starting")
}